Textile treatment with aminoplast and polyacrylamides and the textile so treated



United States Patent TEXTILE TREATMENT WITH AMINOPLAST AND POLYACRYLAMIDES AND THE TEXTILE S0 TREATED William Julius Van Loo, Jr., Middlesex, and Theodore F.

Cooke, Martinsville, NJ., assignors to American Cyananiid Company, New York, N .Y., a corporation of M ne No Drawing. Filed June 13, 1957, Ser. No. 665,606

6 Claims. (Cl. 8-1162) The present invention relates to a process of textile finishing, and particularly to a process for textile finishing for imparting durable hand modifications to textile materials with specific emphasis on imparting durable stiffness to such materials. The invention further relates to the compositions employed in such a process and to the materials so treated.

Heretofore, in the textile finishing industry, finishes have been applied to textile materials which, in addition to imparting dimensional stability, wrinkle recovery and various other properties thereto have incidentally imparted a stilt" hand or stiffness to the treated fabric. In most instances, this quality has only limited durability to home laundering cleaning processes or dry cleaning, depending upon the nature of the treated fabric.

In many instances, certain types of textile materials, such as, for example, viscose rayon, which are used, as for example, in ladies evening wear or in ladies petticoats, the quality of durable stiifness is highly desirable.

Conventional textile treating resins, as for example, melamine-formaldehyde condensates, urea-formaldehyde condensates, including the cylic ureas, such as ethylene urea, 1,2-propylene urea, 1,3-propylene urea, and the like, when employed principally for the purpose of imparting durable stiliness to the treated fabric, require the usage of such high resin solids as to significantly increase the cost of the treated material and in addition the employment of high solids tends to destroy certain other desirable characteristics of the treated material. For example, high resin solids concentrations on certain textile materials, in addition to rendering the material stifi, greatly diminish the materials tensile strength. Thus, while high resin solids may increase such properties as wrinkle recovery and dimensional stability, properties such as tensile strength loss, tear strength, and the like are severely damaged.

An object of the present invention is to provide a composition and a process for treating textile material therewith, whereby said treated material has good dimensional stability, wrinkle recovery, and a durable quality of stiltness or a stilt hand.

A further object is to provide a process for treating such material and a material so treated, in which the quality of durable stilfncss is not achieved at the sacrifice of the quality of tensile strength of the treated material.

These and other objects and advantages are accomplished by a process for treating textile materials that contain groups reactive with a functional group selected from the group CH2OH and CH -0-R, wherein R is a saturated aliphatic radical containing from 1 to 4 carbon atoms, which comprises treating such materials with an aqueous solution comprising (1) a substantially water-soluble, heat-curable, at least difunctional aminoplast resin, and (2) a water-soluble thermoplastic polyamide containing recurring units of the formula:

R! CHa-(. 1

=0 IIIH:

wherein R is a member selected from the group com 3,094,371 Patented June 18, 1963 sisting of H and CH The substantially water-soluble heat-curable aminoplast resin and the water-soluble thermoplastic polyamide are present in the aqueous solution in weight ratios of from 3 to 10% of the former to 1 to 10% of the latter, and the solution is applied so as to add at least about 3% of the aminoplast and at least about 1% of the polyamide based on the dry weight of the textile material. Thereafter, the textile material is subjected to elevated temperatures to dry the material and cure the polyamide and aminoplast in intimate association.

Textile materials that contain groups which are reactive with the melhylol groups or the group defined hereinabove as -CH OH or the alkoxy alkyl group hereinabove defined as CH OR wherein R is a saturated aliphatic radical containing from I to 4 carbon atoms, include cellulosic materials, principal among which are cotton and rayon, though other textile materials that have reactive groups which are capable of entering into a reaction with the treating composition of the present invention may be treated to some advantage.

The present invention is, however, particularly efiective and concerned principally with textile materials that contain cellulosic materials which include mixtures of such materials with other natural and synthetic fibers, which do or do not contain groups reactive with either of the groups, -CH 0H or CH OR.

Both the heat-curable, at least difunctional aminoplast resin and the thermoplastic polyamide are preferably substantially fully water soluble and therefore applied to the textile material as a true aqueous solution. Thus, when the aminoplast resin and the polyamide are in the treating bath or solution they are believed to be substantially unreacted with each other, and to be present therein as separate entities or, if co-reacted, to be so to only the slightest extent, or to an extent which does not significantly affect the solubility of the total mixture in water.

While the heat-curable aminoplast is substantially water soluble and preferably monomeric, degrees of polymerization which are not inconsistent with the substantially water-soluble characteristics of the material are tolerable. So long as the aminoplast resin is not hydrophobic, it may be used in the present invention.

The aminoplast resin of the present invention, in addition to being substantially water soluble and heat curable, must be at least difunctional, i.e. contain at least two methylol groups or at least two alkoxy alkyl groups, or a methylol and an alkoxy alkyl group, both of which are at least theoretically reactive with both the polyamide and the reactive group of the textile material, and in particular cellulosic textile materials.

Suitable examples of such aminoplast resins include urea-formaldehyde condensates, including thiourea and the cyclic ureas, e.g. ethylene urea, l,2-propylene urea, 1,3- propylene urea, and the like. Additionally, melamineformaldehyde condensates and specifically the polymethylol melamine derivatives such as dimethylol, tri, tetra, penta and hexamethylol melamine derivatives and the like. In addition, polymethylol guanamines and substituted guanamines, dimethylol succinamide, the dimethylol derivatives of thio(bis)alkamides and the like are intended to be included.

These and other representative aminoplast resinous materials may be used either alone or in combination with one another, and as their formaldehyde condensates or as their alkylated (etherified) formaldehyde condensates as, for example, in the case of urea, the dimethylated dimethylol urea, in which alkylation or etherification is achieved with saturated aliphatic alcohol containing from 1 to 4 carbon atoms. When alkylated derivatives are used, the monohydric alcohol of the etherifying alkyl group is believed to be split off under the conditions of cure of the present process.

It is believed to be essential to the present invention that the aminoplast be at least difunctional in the present process in order that the individual molecule of the particular material be theoretically capable of reacting under conditions of cure with both the textile material to be treated and with the thermoplastic polyamide compound.

The water-soluble thermoplastic polyamide containing the recurring units above identified are either polyacrylamide or polymethacrylamide. These materials may range in molecular weight from about 50,000 to about 5,000,000 and higher. Those between about 100,000 and 1,000,00 molecular weight have been used with uniformly good success. The molecular weight of the polyamide is of significance in that those having very low molecular weight, for example, those having a molecular weight below 50,000, will not produce the desirable stillness when used in combination with aminoplast resins. The principal limitation with respect to very high molecular weight polyacry'lamides is a practical one. Thus, it has been found that where high molecular weight polyamides as, for example, those having a molecular weight of more than 1,000,000, that the viscosity of the treating solution renders it more difiicult to work with.

As a general rule, the intrinsic viscosity is an indication of the relative molecular weight of the polyamide. Thus, the viscosity of the solution increases as the molecular weight increases. As is well known, if one of the values, its. either the intrinsic viscosity or the molecular weight of the polyamide, is known, the other may be calculated employing the equation:

where [1;] equals intrinsic viscosity, M equals average molecular weight, and K and a are known constants for the given polymer. In the case of polyacrylatmide, K has a value of 3.73 X10" and a=0.66.

Polyamides suitable for use in the present invention should have intrinsic viscosities of from between about 0.4 to about 7.0, as measured in a l-N sodium nitrate solution. These intrinsic viscosities are determined by dissolving various known amounts of the polymer in a l-N sodium nitrate solution and introducing these solutions into an Ostwald pipette. The time required for these solutions to pass through a fixed distance in the pipette is then measured and this value and the densities of these solutions are then divided by the time required for the solvent to so pass through the same fixed distance and its density. In addition, the same data is obtained for the water present in the solvent, so that the viscosity of the polymer may be corrected for both the nitrate and water. The resulting corrected values are termed the relative viscosities. These relative viscosities are then plotted against the concentration of the solutions from which they are obtained and the resulting curve or line is extnapolated to concentration, at which value the intrinsic viscosity is read and obtained.

A critical feature of the present invention resides in the relative weight ratios between the aminoplast resin and the polyam-ide in the composition that is applied to the textile material. The two components should be applied in weight ratios of from 3 to of the aminoplast and from 1 to 10% of the polyamide, based on the weight of the dry textile material. It has further been determined that at least about 1% of the polyamide, based on the dry weight of the fabric, must be present in order to impart the quality of durable stiffness to the fabric.

Thus, between about 4 and of the combined resin solids should be applied to the textile material to achieve the desirable property of durable stillness without seriously adversely aflecting other characteristics of the treated material.

Within the ranges indicated above with respect to the weight ratios of the essential elements applied to the textile fabric, wide variations exist, depending upon which arninoplast and concentration thereof and which concentration of polyamide is employed. Thus, for example,

where the aminoplast resin is dimethylol ethylene urea and 1% of polyacrylamide is employed, it has been determined that in order to achieve a durable stiffness that about 6% of the aminoplast is required on the fabric. In distinction, when 5% polyacrylamide has been applied to the fabric, it has been determined that about 3% of the dirncthylol ethylene urea may be applied and durable stiffness will be achieved. In general, it appears that the more polyacrylamide that is applied to the fabric, the less aminop-last resin is required to achieve the same durability of stiffness. This generality is, however, subject to limitation in that the treated fabric must contain from 3 to 10% of the aminoplast and from 1 to 10% of the polyacrylamide, based on the dry weight of the fabric, to achieve acceptable durable stiffness. In general, the term acceptable durable stiffness may be defined as that percentage of stillness which is retained in a treated material after a 10-cminute process wash (defined more fully hereinafter) and it should be a value of about 50% or more of the initial stiffness achieved through treatment with a composition.

If the percentage of the arninoplast on the textile fabric is significantly in excess of the upper limit indicated above, the treated material would have good initial stiffness and would have good qualities of wrinkle recovery and dimensional stability, but poor tensile strength. In addition, the durability of such stillness is generally not good.

When the polyamide is employed in amounts in excess of the upper limit, as it is defined hereinabove, the treated material would have a good initial and durable stifiness, but other desirable properties, such as, for example, wrinkle recovery and dimensional stability, are of a low order. Furthermore, the viscosity of the treating composition may be too high, with increasing processing difiiculties.

When the textile material has been treated with the aqueous solution of the aminoplast resin and the thermoplastic polyamide, the material is subjected to elevated temperatures in order to dry the same and to ellect a cure of the treating composition.

Drying and curing may be achieved either separately or simultaneously. In order to dry as a separate step, temperatures of the order of from to 275 F. may be employed. In order to cure thereafter, times for from 4 minutes to /5 minute at from 300 to 450 F. may be employed. If it is desired to dry and cure in a single operation, times for from 10 minutes to 3 minutes at from 275 F. to 450 F. may be employed.

The aqueous treating solution of the present invention may be applied by any one of the conventional resin finishing techniques well known to those skilled in the art. Thus, for example, the treating composition may be applied as by spraying, dipping, immersion, or padding.

Normally, the resin composition is applied employing between .6 to 25% of catalyst based on the weight of the aminoplast component of the mixture. Examples of suitable catalysts include the ammonium salts like ammonium chloride, amine salts like triethylamine hydrochloride, alkanolamine salts like triethanolamine hydrochloride, metal salts such as magnesium, zinc and aluminum chlorides, zinc nitrate, and free acids such as oxalic and the like. These may be employed singly or in combination with one another.

A particularly desirable narrower aspect of the present invention relates to the treatment of textile materials with an aqueous solution having a pH adjusted to from between 1 and 3.5 with an acid acting curing catalyst having an ionization constant of at least 10*. Examples of such suitable catalysts are acetic acid, acrylic acid, adipic acid, ammonium acid sulfate, ammonium trihydrogen pyrophosphate, chloroacetic, citric, dichloroacetic, formic, glutaric, glycolic, lactic, maleic, malic, malonic, methyl acid pyrophosphate, oxalic, phosphoric, suocinic, sulfanilic, and tartaric acid. These acids and acid salts,

and others having an ionization constant of at least may be employed singly or in combination with one another. These acids are employed in amounts sutlicient to adjust the pH of the aqueous solution to between the above said 1 and 3.5 pH.

Employment of aqueous solutions containing acid acting catalysts having ionization constants of at least 10- when applied to textile materials, enables the textile material to be dried and cured in a single operation, at times of from between 10 minutes and 5 minutes, at from 175 to 275" F. This is a significant advantage in that normal dry and cure times and temperatures, whether performed separately on the treated material or simultaneously, may be greatly reduced. Thus, for example, where the textile material has been treated with an aqueous solution containing from 2.5 to 5% of polyacrylamide and 10% of dimethylol ethylene urea having a pH of 3, adjusted thereto with phosphoric acid, the material may be dried and cured in a single operation for 5 minutes at 250 F. to impart good properties to the treated material and an outstanding durable stifi hand.

In order that the present invention may be more fully understood, the following examples are given primarily by way of illustration. No details therein should be construed as limitations on the present invention, except as they appear in the appended claims.

EXAMPLE 1 80" x 80" cotton percale was padded through an aqueous pad bath solution containing 5% polyacrylamide and 10% of dimethylol succinamide. The pad bath of the aqueous solution had been adjusted to 3 with phosphoric acid. Thereafter, the treated fabric was run through a padding roll, adjusted to obtain a 100% wet pick-up. The cloth was dried and cured in a single operation for 5 minutes at 250 F.

EXAMPLE 2 A process similar to that employed in Example 1 was followed, except that the material to be treated was viscose rayon.

In order to ascertain the durability of the stifl'ness imparted to the textile material, the materials were tested by a Gurley stiffness tester, which gives the results in milligrams. The higher the value, the greater the stillness. A full description of the Gurley stiffness tester and the method for employing the same, which is a modified Cantilever Bending Method may be found in the Federal Specification CCCT-1916, Textile Test Methods," Method 5202. The two treated samples and an untreated control were so treated. The following are the results in which the larger the number of milligrams the greater the stifiness.

It will he noted from the above table that the present treatment is particularly effective on rayon cellulosic materials, but is also highly efiective on cotton cellulosic material, and that both are vastly superior to the untreated control.

In the above example, the wash durability test comprised washing the textile fabrics in 0.1% soap and 0.1% soda ash at 160 F. for 10 minutes, followed by rinsing, centrifuging, and pressing between each wash cycle. Where 1 hours of washing have been indicated, the above cycle was repeated continuously for 7 hours. The same series of washes was carried out on the rayon piece with the exception that the temperature of washing was F. and no soda ash was employed.

The efiect of washing generally is to break down the stiffness of any fabric, whether it be treated or not. If the finish of the treated material were not durable, little stiffness would be observed after a 10-minute wash and less after 1 hour of washing. The fact that high stiffness values are obtained after 7 hours of washing clearly indicates durability of the finish.

In Table Ii infra, polyacrylamides of varying molecular weights were employed with various thermosetting amino plast resins on cotton and rayon. The treating composition (aminoplast resin plus polyacrylamide) was applied so as to impart 15% solids to the textile fabric consisting of 10% of aminoplast resin and 5% of the polyacrylamide. The polyacrylamide varied in the viscosity, as indicated in the said table, and these resin polyacrylamide mixtures were applied and cured as indicated in the key accompanying the said table. The results of the indicated tests are in miligrams and are otbained on a Gurley stiffness tester.

Table 11 Cotton Rayon Treatment Initial l-hr. Initial l-hr. wash wash 10% methglated ureaformaldehyde 23298 t 6)(1 1tl'insic viscosity 8 0n 211 97 385 20 10% dimetlhlylol ethylene urea plus 2 5% PA I (intrinsic viscosity PAM about 2.0) 218 127 484 182 10% dimethylol suecinarnide plus 5% Pthi 2(ljgtrlnsic viscosity PAM i a on 127 328 245 109? methylated methylol melamine p us 5% PAM I (intrinsic viscosity PAM about 0.12) l2 30 10% dimethylol suonlnaxnlde plus 5% PAM 1 (intrinsic viscosity PAM about 6) 184 101 Untreated 12 30 I HsPOl to pH 3.0 in bath as catalyst. Cloths dried and cured in one operation for 5 min. at 250 F The above table indicates that the above combinations in the respective percentages employed therein will produce a durable stillness on cotton and rayon, and that within wide limits the degree of this durable stifiness was not greatly influenced by the intrinsic viscosity and thus the molecular weight of the polyacrylamide component. As will be noted, a composition employing very low viscosity was not effective as a stiffening agent.

The above table further indicates that efiective durable stiffness can be accomplished with polyacrylamide and resins such as dimethylol succinamide or dimethylol ethylene urea at low curing temperatures, i.e. 250 F. or less, when a free acid catalyst such as phosphoric acid was employed and the bath pH was 3.0 or lower.

In order to prove the significance of the combination of resinous materials employed in the present invention, equal solids concentrations of an aminoplast resin and a medium molecular weight polyacrylamide (M.W. of about 500,000) were applied independently to spun viscose challis and filament nylon twill (IS-ounce) separately, and then equal solids involving the combination of the said aminoplast resin and the medium molecular weight polyacrylamide were applied to similar textile materials. These applications were made on a laboratory padder, obtaining a pick-up of approximately 100% on the viscose and 70% on the nylon twill. 12% of magnesiu-m chloride was employed as a latent acid curing catalyst, based on the amount of the thermosetting resin in all cases. The treated fabrics were dried for 2 minutes at 225 F. and cured 4 minutes at 290 F.

Portions of the treated nylon and viscose cloths were subjected to a l-hour rayon wash consisting of washing in 0.1% soap at 100 F. for 45 minutes, followed by rinsing in water at 100 F. for 10 minutes and minutes in separate cycles. The cloths were then spun dried and pressed on a Hoffman steam press. The washed and unwashed portions of the fabric were then subjected to Gurley stifiness tests and Scott tensile tests. These Scott tensile tests are fully described in A.S.T.M. Standards on Textile Materials," American Society for Testing Materials," November 1953. The results of these tests are shown in Table III.

Table III SPUN VISOOSE CIIALLIS N0'rl:.12% magnesium chloride employed on Resin A solids. Cloths dried 2 min. at 225 F. and cured 1 min. at 290 F. Resin A-Trimethoxy trirneth ylol melamine.

Table III indicates that no significant durable stiflness was produced on filament nylon by any of the treatments. With respect to the viscose, n0 significant durable stiifness was imparted by resin A alone, and while a high order of stiffness Was imparted by the poiyacrylamide when employed alone, this stiiiness was not significantly durable to washing. Where the combination of polyacrylainide and resin was employed, the stiffness o'b tained was about /3 that obtained from the application of polyacrylamide alone, and since only Va as much polyacrylamide was employed in the combination, the order of stiflness obtained was proportional. Moreover, the

stillness of the combination was extremely durable to washing with about 75% of the imparted stiifness retained after washing. It is also apparent that the resinpolyacrylamiide combination caiused less strength loss than either the resin or polyacrylamide alone. The addition of V: of the strength loss obtained with polyacrylamide alone and We of the strength loss obtained with the resin alone, since these are the proportions used in the combination, would be double the observed loss in strength obtained with the combination. The combination of resin and polyacrylamide is therefore synergistic in durability of stiifness and retained tensile strength.

In order to determine the minimum eifective amount of polyacrylamide which must be present on the treated textile fabric, a series of experiments were run in which the concentration applied varied in amounts from between 0.l% and 5%, based on the weight of the treated fabric. The treated fabric was spun viscose challis and the polyacrylamide imparted thereto 'was dried for 3 minutes at 300 F. In addition to the wash procedure described hereinabove, portions of the treated fabric were subjected to three dry-cleaning cycles in a Dynamic Absorption tester for 20 min. each in Varsol No. 2, followed by drying and steam pressing at the end of the third cycle. The physical properties were determined as hereinabove.

Table IV EFFECT OF CONCENTRATION OF POLYACBYLAMIDE ON PROPERTIES OF SPUN VISCOSE CHALLIS Gurley stifiness l Polyacrylamide (medium Tensile, viscosity) concentration initial (percent) Initial l-hr. 3 dry wash cleanings 1 Total warp plus filling.

Table IV indicates that the degree of stifiness imparted is proportional to the concentration of polyacrylamide on the fabrics, and that a minimum of about 1% polyacrylamide is necessary to substantially increase the initial stiffness of the fabric.

Table V COMPARISON OF POLYAORYLAMIDE-RESIN OOMBINATIONS 1% Polyacrylamide Gnrley stiflness l Tensile strength, intial Molar ratios 1 Percent resin solids Initial Washed A B O A. B 0 A B 0 55. 6 6B 43. 3 43. 9 79 82 73. 3 25. 0 31. 7 36. 7 89 94 73. 3 19. 5 16.1 19. 5 99 105 81 66. B 16. 7 86 62. 2 14. 5 14. 5 16. 1 98 92 01 68. 8 16. 4 l6. 1 90 6% Polyau'ylamide Aminoplast Resin olyacrylamido.

imethory 1 Total warpqplus flil i n Nora.-A= r melamine.

trlmethylol melamine; B=d1methylo1ethlene urea; O=trimethory pentamethylol In the next study, the amounts of various resins required to eifect durability of the stifiness imparted by either 1 or of a polyacrylamide (M.W. of about 500,000) were determined. Since polyacrylamide is a multiple of the molecular weight of this unit (71) was employed in determining molar ratios of resin and polyacryiarnide. Applications were made as before to viscose challis of a number of appropriate molar combinations. Physical properties were determined as before but the dry cleaning tests were omitted.

The results shown in Table V indicate that the durability of stiffness imparted by polyacrylamide is increased as the ratio of resin to polyacrylamide is increased. Table V further indicates that where the amount of aminoplast resin employed is significantly less than about 3% solids based on the weight of the textile fabric, a desirable durable stifiness is not obtained.

Heretofore, various polymeric materials have been employed for purposes of imparting stifiness to textile fabrics. One such polymeric material is commercial polyvinyl alcohol. In order to illustrate the superiority of the combination of the present invention over the combination of commercial stifiening materials with aminoplast resins, the following experiments were run in which polyvinyl alcohol (Elvanol 51-05) and a polyacrylamide having an average molecular weight of about 500,000 were mixed in varying amounts with thermosetting resins A and B, which are trimethoxy trimethylol melamine and dimethoxy dimethylol ethylene urea, respectively. These resinous mixtures were prepared and employed in the relative concentrations indicated in the said table. In all cases, the polyvinyl alcohol and polyacrylamide were employed in amounts of 5% based on the weight of the textile material, which was as much initial stitl'ness and stiffness after washing, when employed at equivalent solids as that obtained when the polyacrylamide-resin combination of Table V1 is employed.

The term intimate association" is employed herein with reference to the drying and curing of the aminoplast and polyamide together, in view of the lack of certainty with respect to the manner in which the aminoplast and polyamide may react under curing conditions with each other or the textile material. It is intended to include all such variations.

Although the present invention has been described with particular reference to the treatment of cotton and viscose rayon, and more specifically cotton and rayon fabrics, the treatment herein described may also be applied to other textiles which are principally composed of cellulose or regenerated cellulose, for example, linen, hemp, jute, ramie, sisal, viscose rayons, cuprammonium rayons, and mixtures thereof, with each other or with non-cellulosic fibers, such as, for example, nylon, polyester fibers, acrylics, and the like.

The terms textile" and "textile materials as used generally herein and in the appended claims, include within their meaning filaments, fibers, threads, yarns, twisted yarns, etc. as such, or in woven, non-woven or otherwise formed fabrics, sheets, clothes, and the like.

In addition to the essential components of the treating composition set forth hereinabove, namely the aminoplast resin and the polyamide, and the acid acting curing catalyst, other additives which are not inconsistent and do not destroy the effect of the essential components of the present invention may be added therewith, as for example, softeners, antistatic agents, fillers, pigments, dyes, and the like, may be incorporated into the treating solution and applied simultaneously with the resin composition of the present invention.

We claim:

1. A process for treating textile materials containing groups reactive with the group CH OH to impart durspun viscose rayon challis. 40 able stifiness thereto which comprises treating said ma- Table VI COMPARISON OF POLYACRYLAMIDE AND POLY VINYL ALCOHOL Gurley stillness Tensile strength, Initial Initial Washed Molar ratio PVA PAM PVA PAM PVA PAM A Percent B Percent A Percent B Percent A B A B A B A B resin resin resin resin 1/1 126.5 10 305.3 10 58.9 188.7 .a- 61 48 12-- 157.6 10 244.6 10 272.4 5 87.7 186.5 175.4 56 67 49 11/5" 124.3 4 122.1 2.5 224.2 3.5 68.8 15.4 73.3 76 85 72 1/10 129.9 0 102.1 1.25 278.0 1 61 15.8 27.8 83 85 120-- 183.5 0.9 81 74 ntreated son) 17.5 1 2) 1 Aminoplastlpolymer.

The results of Table VI indicate that polyvinyl alcohol, a commercial stifl'ening agent, imparts only about of the stifiness obtained with polyacrylamide in equivalent applications.

Table VI further indicates that when the concentration of aminoplast resin imparted to the textile material falls significantly below the 3% minimum required that the property of durable stiffness is significantly reduced.

Solvitose HDF, a modified starch frequently employed as a stifiening agent for cellulosic textile materials, was also mixed with aminoplast resin A and aminoplast resin B in a manner similar to that set forth hereinabove in connection with Table VI. The results of this comparison indicate that Solvitose HDF imparts approximately 36 terial with an aqueous solution consisting essentially of l) a substantially water-soluble, heat-curable, at least difunctional aminoplast, (2) a water-soluble thermoplastic polyamide selected from the group consisting of polyacrylamide, polymethacrylamide and mixtures thereof, and (3) an acid acting curing catalyst for said aminoplast. said (1) and (2) being present in aqueous solution in weight ratios of from 3 to 10% of the former and 1 to 10% of the latter, wherein at least 1% of the polyamide is applied to the material based on its dry weight and thereafter subjecting said material to elevated temperatures to cure (I) in intimate association with (2).

2. A process for treating textile materials containing groups reactive with the group CH OH to impart dill" able stillness thereto which comprises treating said material with an aqueous solution consisting essentially of l) a substantially water-soluble, heat-curable, at least difunctional melamine-formaldehyde condensate, (2) a water-soluble thermoplastic polyamide selected from the group consisting of polyacrylamide, polymethacrylamide and mixtures thereof, and (3) an acid acting curing catalyst for said melamine-formaldehyde condensate, said (1) and (2) being present in aqueous solution in weight ratios of from 3 to 10% of the former and 1 to 10% of the latter, wherein at least 1% of the polyamide is applied to the material based on its dry weight and thereafter subjecting said material to elevated temperatures to cure (1) in intimate association with (2).

3. A process for treating cellulosic textile material containing groups reactive with the group -CI-I OH to impart durable stiffness thereto which comprises treating said material with an aqueous solution having a pH of from about 1 to 3.5 comprising (1) a substantially watersoluble, heat-curable, at least difunctional aminoplast, (2) a water-soluble thermoplastic polyamide selected from the group consisting of polyacrylamide, polymethacrylamide and mixtures thereof, and (3) an acid acting curing catalyst having an ionization constant of at least 10- said (1) and (2) being present in said aqueous solution in weight ratios of from 3 to 10% of the former and 1 to 10% of the latter, wherein at least 1% of the polyamide is applied to the material based on its dry weight, and thereafter subjecting said material to elevated temperatures to cure (l) in intimate association with (2).

4. A process for treating cellulosic textile material containing groups reactive with the group CH OH to impart durable stiffness thereto which comprises treating said material with an aqueous solution having a pH of from about 1 to 3.5 comprising (1) a substantially watersoluble, heat-curable, at least difuctional melamine-formaldehyde condensate, (2) a water-soluble polyacrylamide, and (3) an acid acting curing catalyst having an ionization constant of at least 10 said (1) and (2) being present in said aqueous solution in weight ratios of from 3 to 10% of the former and l to 10% of the latter, wherein at least 1% of the polyacrylamide is applied to the material based on its dry weight, and thereafter subjecting said material to elevated temperatures to cure (1) in intimate association with (2).

5. A composition of matter suitable for imparting durable stitfness to cellulosic textile materials which consists essentially of an aqueous solution containing (1) from between 3 and 10% of a substantially water-soluble, heatcurable, at least difunctional aminoplast and (2) from 1 to 10% of a Water-soluble thermoplastic polyarnide selected from the group consisting of polyacrylamide, polymethacrylamide and mixtures thereof.

6. A cellulosic textile fabric having a durable stiff finish that consists of an intimately associated mixture of from 3 to 10% of a water-insoluble, heat-cured aminoplast and from 1 to 10% of a polyamide selected from the group consisting of polyacrylamide, polymethacrylamide and mixtures thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,173,005 Strain Sept. 12, 1939 2,313,742 Engelmann Mar. 16, 1943 2,355,265 Bock Aug. 8, 1944 2,524,111 La Piana Oct. 3, 1950 2,653,140 Allenby Sept. 22, 1953 2,810,624 Wardell Oct. 22, 1957 2,819,237 Daniel Jan. 7, 1958 2,886,474 Kline May 12, 1959 2,971,931 Glade Feb. 14, 1961 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,094,371 June 18, 1963 William Julius Van Loo, Jr., et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Columns 7 and 8,Table V, sixth column, line 2 thereof, for

"48.3" read 42.3 columns 9 and 10, Table VI, first column, lines 2 and 3 thereof, for "/2" and "11/5", respectively, read 1/2 and--1/5 respectively; same columns 9 and 10,

same Table VI, third column, line 4 thereof, for "0" read Signed and sealed this 24th day of December 1963.

(SEAL) Attest: EDWIN L. REYNOLDS ERNEST W. SWIDER Attesting Officer Ac ting Commissioner of Patents UNITED STATES PATENT OFFICE Patent No. 3,094,371

corrected below.

Columns 7 and 8, Table V, "43. 3" read 42.3 lines 2 and 3 thereof,

-- 1/2 and --1/5 It is hereby certified that ent requiring correction and that William Julius Van Loo, Jr. et al 1 error appears in the above numbered pat-- the said Letters Patent should read as sixth column CERTIFICATE OF CORRECTION June 18, 1963 line 2 thereof, for

columns 9 and 10, Table VI first column,

for "/2" and "11/5", respectively, read respectively; same columns 9 and 10,

same Table VI third column, line 4 thereof, for "0" read l SEAL Attest:

ERNEST W. SWIDER Attesting Officer EDWIN L. REYNOLDS Ac 1; ing Commissioner of Patents 

1. A PROCESS FOR TREATING TEXTILE MATERIALS CONTAINING GROUPS REACTIVE WITH THE GROUP -CH2OH TO IMPART DURABLE STIFFNESS THERETO WHICH COMPRISES TREATING SAID MATERIAL WITH AN AQUEOUS SOLUTION CONSISTING ESSENTIALLY OF (1) A SUBSTANTIALLY WATER-SOLUBLE, HEAT-CURABLE, AT LEAST DIFUNCTIONAL AMINOPLAST, (2) A WATER-SOLUBLE THERMOPLASTIC POLYAMIDE SELECTED FROM THE GROUP CONSISTING OF POLYACRYLAMIDE, POLYMETHACRYLAMIDE AND MIXTURES THEREOF, AND (3) AN ACID ACTING CURING CATALYST FOR SAID AMINOPLAST SAID (1) AND (2) BEING PRESENT IN AQUEOUS SOLUTION IN WEIGHT RATIOS OF FROM 3 TO 10% OF THE FORMER AND 1 TO 10% OF THE LATTER, WHEREIN AT LEAST 1% OF THE POLYAMIDE IS APPLIED TO THE MATERIAL BASED ON ITS DRY WEIGHT ANND THEREAFTER SUBJECTING SAID MATERIAL TO ELEVATED TEMPERATURES TO CURE 81) IN INTIMATE ASSOCIATION WITH (2). 